<template>
  <div>
     <router-link
      tag="div"
      to="/"
      class="header-abs"
      v-show ="showAbs"
     >
      <div class="iconfont header-abs-back">&#xe624;</div>
     </router-link>
    <div
      class ="header-fixed"
      v-show ="!showAbs"
      :style = "opacityStyle"
     >
       <router-link to="/">
           <div class="iconfont  header-fixed-back">&#xe624;</div>
       </router-link>
        景点详情
    </div>
  </div>
</template>

<script>
export default {
  name: 'DetailHeader',
  data () {
    return {
      showAbs: true,
      opacityStyle: {
        opacity: 0
      }
    }
  },
  methods: {
    handleScroll () {
      const top = document.documentElement.scrollTop
      if (top > 60) {
        let opacity = top / 140
        opacity = opacity > 1 ? 1 : opacity
        this.opacityStyle = {
          opacity
        }
        this.showAbs = false
      } else {
        this.showAbs = true
      }
    }
  },
  activated () {
    window.addEventListener('scroll', this.handleScroll)
  },
  deactivated () {
    window.removeEventListener('scroll', this.handleScroll)
  }
}
</script>

<style lang="stylus" scoped>
   @import '~styles/varibles.styl'
  .header-abs
    position: absolute
    left: .2rem
    top: .2rem
    width: .8rem
    height: .8rem
    line-height: .8rem
    border-radius: .4rem
    text-align: center
    background: rgba(0, 0, 0, .8)
    .header-abs-back
      color: #fff
      font-size: .4rem
  .header-fixed
     z-index: 2
     position: fixed
     top: 0
     left: 0
     right: 0
     height: $headerHeight
     line-height: $headerHeight
     text-align: center
     color: #fff
     background: $bgColor
     font-size: .32rem
     .header-fixed-back
       position: absolute
       top: 0
       left: 0
       width: .64rem
       text-align: center
       font-size: .4rem
       color: #fff
</style>
